Men who have much to say use the fewest words.

Mastery compresses. When you understand something thoroughly you can hand over the essential part in a sentence, because you know which parts are essential; when you half understand it, everything seems necessary and you deliver all of it. Length is often a sign of unfinished thinking rather than depth. The work of getting short is the work of getting clear.

Take something you know well and try explaining it in three sentences to someone with no background. Where you cannot compress, you have found the place your own understanding is still vague. Go and fix that rather than adding more words around it.